Abstract: In order to allow bit-interleaved-parity calculation to be easily performed while maintaining compatibility with an existing system during transmission of data having mixed bit rates, header information of a first bit rate is added to data of the first bit rate and data of a second bit rate, time-division multiplexing is performed on the header-information-added data signals to generate a data string and a frame header is added thereto to generate a frame signal, parities of the frame signal that is sequentially generated are determined, parity bits for parity checking for the data signals of the first bit rate and the data signals of the second bit rate are inserted into the frame signal, based on a result of the parity calculation.

Abstract: In a digital filter device which filters a plurality of signals by a single digital filter, an input data memory stores the input data strings generated by computing processors, and a digital filter reads the input data strings in a predetermined sequence to be filtered and generates output data strings. An output data memory stores the output data strings, and a data processor reads the output data strings in a predetermined sequence to be processed. Furthermore, a filter memory and coefficient memories respectively store data-under-calculation and a filter coefficient in a delay circuit included in the digital filter.

Abstract: A mirror controller of an optical switch comprises a signal generator (10, 82, 83) for passing the optical signal on the same light path as the one for optical communication using the optical switch, and an image analyzer (15, 16, 81) detecting the optical signal as the light scattered by at least one of tilt mirrors (111, 123) and an output collimator array (14). The image analyzer detects the position of the light beam image as a control position (121, 141, 85) based on the scattered light, and controls the tilt mirrors in such a manner that the detected control position coincides with the predetermined desired target position (122, 142, 84, 86) on at least one of the tilt mirrors and the output collimator array. The mirror controller can realize the connection test of the optical signal between input and output with high accuracy and reliability.

Abstract: An optical transmission system (1) alters quantity of incident light by reflecting an optical signal by a micro mirror (11) to enter an optical fiber (13) and by controlling an angle of the micro mirror (11), so that attenuation of the optical signal is controlled. An optical filter (14) is disposed between the micro mirror (11) and the optical fiber (13), for correcting a relationship between a control angle or control voltage of the micro mirror (11) and attenuation of the optical signal to be close to a linear relationship.

Abstract: A wavelength selective switch module is disclosed.

Abstract: An output control unit outputs data of bit rate A to a first header-attaching unit and data of bit rate B to a second header-attaching unit. An instructing unit instructs the first or the second header-attaching unit to attach a header of bit rate being the least bit rate to the data of bit rate A or B. The first header-attaching unit creates a header of bit rate A, including an ID of a destination ONU of the data of bit rate A and information concerning the data length, and attaches the header of bit rate A to the data of bit rate A. The second header-attaching unit creates a header of bit rate A, including an ID of the destination ONU of the data of bit rate B and information concerning the data length, and attaches the header of bit rate A to the data of bit rate B.

Abstract: A first header-attaching unit attaches to data of a low speed bit rate A, a header of the bit rate A. A second header-attaching unit attaches the header of the bit rate A to data of a high speed bit rate B. A combining unit combines outputs of the first and the second header-attaching units. A low speed scrambling unit performs a scrambling process on combined data by using a clock corresponding to the bit rate A. A high speed scrambling unit performs a scrambling process on the data of the bit rate B by using a clock corresponding to the bit rate B. During a timing corresponding to the bit rate A in the frame, a selector selects an output of the low speed scrambling unit. During a timing corresponding to the bit rate B in the frame, the selector selects an output of the high speed scrambling unit.

Abstract: Regarding the passive optical network (PON) system of the present invention, in an OLT, data of different bit rates is framed, and framed data rows are subjected to FEC encoding processing without changing the line up of the data, and a check bit is added to the end of the frame, and an optical signal that has been modulated in accordance with the data row to which the check bit has been added is transmitted to the optical transmission line. Then in an ONU that corresponds to a high speed bit rate to which an optical signal from the OLT has been applied via a power splitter, forward error correction of the reception data is performed. As a result in a PON system in which data of different bit rates coexist, the minimum reception rate of a high speed ONU can be improved without having an influence on a low speed ONU.

Abstract: An object of the invention is to provide a control apparatus and a control method having a simple constitution, which can stably perform switching of optical path in an optical signal exchanger, while suppressing an influence on a control due to the mechanical resonance of tilt mirrors. To this end, the control apparatus of the optical signal exchanger is constituted such that in an optical signal exchanger of three-dimensional type using one set of MEMS mirror arrays, each having a plurality of tilt mirrors arranged on a plane, each tilt mirror having a reflecting surface an angle of which is controllable, when the angle of the MEMS mirror on the optical path is feedback controlled by detecting power of an optical signal output from a specific position, a resonance component removing section that removes a resonance frequency component included in a control signal is shared corresponding to a pair of driving electrodes arranged in a coaxial direction of the MEMS mirror.

Abstract: A polarization independent optical isolator includes: a first birefringent plate that divides the receiver light from the optical transmission path into normal light and abnormal light to output the normal light and the abnormal light; a second birefringent plate that combines the normal light and the abnormal light to output the combined light to the light receiving element; an optical rotation unit that is disposed between the first birefringent plate and the second birefringent plate, rotates the polarization direction of the normal light and the abnormal light which are outputted from the first birefringent plate by substantially 90° and outputs the rotated light, and outputs the reflected light of the receiver light in a state where the polarization direction of the reflected light is not rotated; and a polarizing element that is disposed between the optical rotation unit and the second birefringent plate, allows one of the normal light and the abnormal light which are inputted from the optical rotation

Abstract: The present invention is a wavelength superimposing device that can restrain a system scale and further reduce an optical transmission loss, while broadcasting a video signal light in a WDM network system, a manufacturing method therefor, and the WDM network system, and comprises a filter device that reflects some light of an input wavelength-multiplexed light in a direction different from an optical path direction of the input wavelength-multiplexed light and transmits a light of remaining wavelengths, a first optical system in which a reflected light reflected by the filter device is re-incident on a plurality of incident positions on a reflecting surface of the filter device, and a second optical system in which a transmitted light from the filter device is spectrally separated for each wavelength and each separated light is incident on the plurality of incident positions from a transmission surface of the filter device.

Abstract: The present invention is a method of transmitting data of different bit rates in a simple manner and, if positive minimal multiples whose multiple operation values on the bit time lengths 1/Ai for a plurality of communication bit rates Ai become common are minimal multiples ai respectively, an optical line terminal constitutes a time division multiplex signal composed of a first data area having a bit rate Ai/ai and including frame synchronization information and a second data area in which packets addressed to each optical network unit of the bit rate Ai are time division multiplexed, and transmits the time division multiplex signal to a plurality of optical network units via a branching/multiplexing means.

Abstract: A wavelength selective switch module is disclosed.

Abstract: A MEMS optical switch device is disclosed that includes an optical system deflecting and outputting light signals; first and second test light generation parts generating and feeding first and second test lights to specific input and output ports, respectively, of the optical system; first and second divergence parts diverging the first and second test lights, respectively, from the optical system; first and second monitoring parts detecting the diverged first and second test lights, respectively; and an operational check part causing the first and second test lights to be incident on output and input deflection parts of the optical system by driving a specific input deflection part corresponding to the specific input port and a specific output deflection part corresponding to the specific output port, respectively, and performing an operational check on the output and input deflection parts from the light levels of the detected first and second test lights, respectively.

Abstract: A wavelength locker includes: a birefringent plate for separating light emitted from a light source into two beams of light which are approximately in parallel to each other; a first light receiving element for directly receiving one of the two beams of light separated by the birefringent plate; a ?/4 plate and an etalon filter through which other one of the two beams of light separated by the birefringent plate passes; and a second light receiving element for receiving the other one of the two beams of light which has passed through the etalon filter. The ?/4 plate has an optic axis tilted at 45 degrees with respect to a polarization direction of light incident on the ?/4 plate, changes a polarization direction of light, which has been reflected by the etalon filter and incident on the ?/4 plate, such that the reflected light does not return to the light source after passing through the birefringent plate, and emits the resultant light.

Abstract: A polarization independent optical isolator includes: a first birefringent plate that divides the receiver light from the optical transmission path into normal light and abnormal light to output the normal light and the abnormal light; a second birefringent plate that combines the normal light and the abnormal light to output the combined light to the light receiving element; an optical rotation unit that is disposed between the first birefringent plate and the second birefringent plate, rotates the polarization direction of the normal light and the abnormal light which are outputted from the first birefringent plate by substantially 90° and outputs the rotated light, and outputs the reflected light of the receiver light in a state where the polarization direction of the reflected light is not rotated; and a polarizing element that is disposed between the optical rotation unit and the second birefringent plate, allows one of the normal light and the abnormal light which are inputted from the optical rotation

Abstract: In an optical switch controller, in order that residual vibration at movement control of a movable body such as a tilt mirror can be reduced and controlled with high accuracy, a processing unit outputs a driving signal for controlling the angle of the tilt mirror, the driving signal is D/A converted by a D/A converter and then is changed to a high-voltage signal by a high-voltage amplifier to be supplied to the tilt mirror, the electrostatic capacity of the tilt mirror changes corresponding to angle change of the tilt mirror, a mirror-angle detecting unit detects the electrostatic capacity and feeds back it as a correction value to a processing unit, and the processing unit corrects the driving signal using a correction value obtained when the angle of the tilt mirror is actually changed.

Abstract: The present invention relates to a multi-bit-rate optical communication method, optical network units, and an optical line terminal that enable multi-bit-rate transmission of low bit-rate data and high bit-rate data while maintaining compatibility with existing systems and reducing upgrade costs of optical network units and labor required for the upgrade, wherein the optical line terminal transmits a first data area including frame synchronization information in a predetermined frame format at a first bit rate and a second data area at a second bit rate which is the first bit rate×Mdown (Mdown>1), and any of the optical network units performs reception processing at a rate once every Mdown-bit to detect the frame synchronization information in the first data area and, based on detection timing thereof, performs reception processing of the second data area by a bit.

Abstract: In an optical telecommunication system in which an intensity of an arriving optical signal is different for each packet, detected is an optical intensity for each packet with little error. For this purpose, contrived is to detect an average optical intensity across header parts for each packet by focusing on the fact that the header part comprising the preamble and delimiter of a packet is in a bit pattern which includes approximately the same numbers of “0” and “1”.

Abstract: A light source supplies optical signal to an optical switch and a detector detects light receiving level. A control unit changes a deflection control amount for changing an angle of a tilt mirror, and outputs the deflection control amount to a driving unit. When an input and an output ports are same, optical offset of the tilt mirror is calculated based on optimal angle at which the light detector detects an optimal point of the light receiving level. Whenever the input and the output port are different, a structure parameter of the tilt mirror is calculated based on the optical offset and the optimal angle. The optical offset and the structure parameter are stored in a memory as a test result.